Machine for making flexible metallic tubes



Dem-22, 1942. A. F..LAPP ErAL 2,305,587'

MACHINE FOR MAKING FLEXIBLE METALLIC TUBES ATTORNEY Dec. 22, 1942. A. F. LAPP Erm.

MACHINE FOR MAKING FLEXIBLE METALLIC TUBES Filed March 14, 1941 4 Sheets-Sheet 2 INVENTORS ATTORNEY 'illy "il Dec, 22, 1942. A; F, LAPP Erm, 2,305,587

ummm Foa' mme FLE-:xmms unnnuc Tunas Filed laren 14, 1941 4 sheets-sheet s INVENToRs Maf/e7' APP I HERMA/y jfffunfk ATTORNEY Dec. 22, 1942. A. F. LAPP Erm. 2,305,587

KACHINE FOR MAKING FLEXIBLE METALLI()y TUBES Filed llarch 14, 1941 4 Sheets-Sheet Patented Dee. 22, 1942 MACHINE FOB MAKING FLEXIBLE TUBES Albert F. Inpp and Herman Sheiimer, Newark, N. J., assignors to Breexe'Corporations, Inc., NewarhN. J., a corporation o! New Jersey `Application March 14, 1941, Serial No. 383,298

15 Claims.

This invention relates to a machine for producing flexible tubing.

It is common practice to manufacture ilexible tubing from a continuous strip formed with convolutions which are interlocked so as to provide a seam. In some applications of exible tubing, particularly in the aircraft industry, it is essential that the tubing be airtight and watertight.

-Under the stress of service where the tubing is subjected to intense vibration and other strains, the seams will not stand up and the tubing does not remain iiuid tight. The broad object of the present invention is to produce a flexible tube which will withstand the strains of service and yet remain fluid tight, and air tight.

In order to overcome this difficulty it has been known in the past to introduce a thread of solder into the seam of the tubing and, by the application of heat, provide a soldered joint. The objection to such construction is that each convolution of the tube is a seam., which seam in continuous, and of necessity zap/considerable portion of the stress of flexing the tube must be carried by the seam, with the result that even a soldered seam is subject to breakdown. A flexible tube can be made so that Iapparently no stress is applied to the seam with the result that no breakdown will occur by reason of the seam opening. This result is accomplished by providing a strip of metal having a plurality oi" convolutions so that onlyA every second or third convolution forms the seam. Accordingly, the primary object of this invention is to provide a flexible tube formed of a single strip having interlocked edges and provided with intermediate convolutions to permit flexibility without imposing strain on the seams.

Figure 2 is a vertical section, partly in elevation, and partly in perspective, taken approximately on lines 2--2 of Figure l, lookingv in the direction indicated by the arrows.

Figure 3 is a plan view of the die plate and dies for preforrning the strip;

Figure 4 is a side elevation of the dies shown in Figure3, partly broken away:

Figure 5 is an end elevation of the dies shown in Figure 3, partly broken away;

Figure 6 is a longitudinal section, partly in elevation, through the operating head of the maaway, taken approximately on line 1-1 of Figure 6, looking in the direction indicated by the arrows;

Figure 8 is a section, taken approximately on line l-B of `Figure 6, looking in t-he direction indicated by the arrows;

Figure 9 is an expanded edge elevation of one forming die and the spacer which separates it from the succeeding die; l

Figure 10 is an enlarged, fragmentary transverse section, taken through the forming die;

Figure 11 is a transverse section, taken approximately on line iI-i I of Figure 10, looking in the direction indicated by the arrows;

Figure 12 is a side elevation of a section of tubing with an extended portion of the strip material shown in perspective.

Figure 13 is a fragmentary detail in section, taken approximately on line I3-l3 of Figure l2, looking in the direction indicated by the arrows, and showing the' contour of the strip material A after having been preformed in the die of Figures A further object of the invention is to provide a simple machine for carrying the foregoing objects into effect which machine may be readily used for manufacturing tubing of various sizes. A further, more specific object of the invention is to provide a machine having a compound die so that by'change of parts of the die different sizes of tubing may be made- The invention consists of the construction, combination and arrangement of parts described and claimed.

In the accompanying drawings, forming part hereof, is illustrated one form of embodiment of the invention, in which drawings similar reference characters designate corresponding parts, and in which:

Figure 1 is a side elevation showing the general setup oi' the machine;

3, 4 and 5;

Figure 14 is a fragmentary detail in section,

taken approximately on line |4-l4 of Figure 12,`

looking in the direction indicated by the arrows;

Figure 15 is a side elevation of a section of tubing mounted on a fixture for the purpose of longitudinal compression after the tubing has been made;

Figure 16 is a view similar to Figure 15, but showing the tubing after it has been compressed;

Figure 17 is an enlarged section, partly in elevation, after the tube has been compressed, showing the flexibility of the tube without flexing the seam Figure 18 is a fragmentary detail in section of a modied type of tube in which the seam is formed at the base rather than at the crown of the convolutions; and,

Figure 19 is a fragmentary detail showing 'the contourfof the seam-forming die at the point where the preformed strip enters the dies and at the point where the seam is completed by turning the edge of the strip over on the adjacent edge of the next convolution.

Figure 20 is a fragmentary detail in section of a tube in which the seam is formed at the crown of the convolutions.

Referring to the drawings, and particularly Figure l, 2F designates a base on which is mounted a hollow stand 2l. Carried by the stand. 2l is a horizontal arm 22 on which is mounted a bath tenir 23 containing flux 2li. Carried by the stand t is a reel 25 having a supply oi strip material 2t which is fed over a wheel 2l, carried by the tank til, and under a wheel 28 so that the strip to ls covered on both sides with the liquid fluir it.

The strip 2t then passes through a wiping element 2o, which is so arranged that the surplus nur. on both sides of the strip 26 is removed and the strip 2B proceeds with an even coating of ux on both sides. VThe hux 24 may be of any well known composition, common in the art of soldering. The advantage of applying the flux to the strip is that all parts of the eventually soldered seam will have an application of flux applied thereto, Whereas, if the ux is merely applied to the solder it may not be dispersed throughout the seam, and a weak soldered seam will result.

Carried above the stand 2l is a forked :adinstable bar @il which supports on its outer end a rwheel iii over which the strip 2t passes to a set oi dies `which are designated generally as 32. The dies are more fully disclosed in connection with the description of Figures 3, d and 5, and their function is to preform the strip 26 to the contour shown in Figure i3. The dies 82 are adjustable on the bar lo and are held in ad iusted position by a wing nut 533.

iter leaving the dies d? the strip 2S proceeds to the operating head designated generally as 3B and as more fully disclosed in connection with the description of Figures 6, etc., where the actual ilegible tube is formed.

Carried by the support ann 22 is a bracket on which is mounted a spool @t of solder Si. lin a tuba-forming operation, as hereinafter de scribed, the thread of .solder 3l is introduced in the scam during the forming operation so that the solder till is completely disposed in the seam.

l The operating head @il is actuated through the medium of a drive belt tti connected to the usual idler and drive pulleys liti, the change from idler to drive pulley being accomplished by an ordinary d@ sstuated by a control lever i3 i in the well isnotvn manner. il. drive shaft l2 is operated by the drive pulley Btl, and operates a belt to a pump dd ior supplying .a lubricant to the tube forming die through d having a nozzle at a position above the operating head tid.

Under the operating-head 35i, winch includes the iorrning dies, hereinafter described, is disposed a catch basin fil provided with a strainer which the lubricant may be returned.

to the hollow stand 2li trom which it repeats the cycleoi now through a return pipe dit, and the pump to the nomic do. The lubricant used may be of any desired composition well known in the art for its intended function.

Referring to Figure 2, it will be readily ob" served. that the shaft d2 is supported from the hearing supports it@ and is provided with a rid pulley 5I which drives a belt 42, and a pulley 53 which operates the head 34. When the machine is operated the flexible tube is formed in the forming dies and progresses to the left of Figure 2 as a completed tube 54 having the solder il incorporated in the seam. The tube 54 then passes through aheating coil 55 which surrounds a glass or other suitable tube 56 and forms part of-a high frequency electrical induction heat apparatus designated generally as 51 which ls provided with the usual controls 58. The coil 55 is normally copper tubing and not only acts as conductor, but carries a ow of water for coolingpurposes. The use of high frequency induction heat is' well known in other arts, and need not be fully described here. It uses a high frequency oscillator producing high frequency alternating current, which, when passed through the inductive coil et produces a rapidly alternating magnetic eld. When the tube 54 is passed through the held a high, readily controlled heat is applied to the tube 5th This ouickly melts the solder 'Si and causes an even dispersion of the solder through the entire seam by reason of the fact that the entire strip 26 is coated on both sides `with the flux 2d.

Below the heating coil 55 is disposed a trough be adapted to catch any surplus flux or lubricant which may drip from the finished tube. As the tube @il proceeds to the left of Figure 2 it is received in a chute t@ which may be of any desired length and is preferably straight to prevent flexing of the tube 5d until the solder 3l has set and the tube 5ft has cooled. sited length ci the tube 54 has been made, or when all of the material o'n the reel 25 has been used up, the nished tube 5B. may be removed from the chute @il for further processing, as

hereinafter described.

v Referring to Figures 3, 4 and 5, the performing die S2 consists of a roller die case in which 'are mounted a set of three progressive dies o2,

rotatable on fixed stub shafts G3. The three dies t?. are progressive, the first die serving to make grooves in the strip 2S, the second die being intended to form the grooves into definite depressions, and the third die to continue the operation to form the strip 26 to the contour nnaily secured, as shown in Figure 13. Complernentary dies tl are provided for each die 52 and are held in heating blocks t5 in the die case di, @rassure screws @t are provided so that proper adjustment may be made between the-dies @d and the dies @52.

@n the front of the die case Si is mounted an extension i'l carryirm an adjustable block to for nllgg the vstrip 2&5 with the dies B2 and dit. n transverse shaft @d carrying an adjusting nut liti is provided for aligning the strip 2o to the block @d with the dies t2 and od. The shaft is provided with a spring il and a pin i2 which is mounted in the die case di to prevent turning of the shaft te. By adjustment of the nut l@ the blo-cls t@ may be moved latereliy to bring the strip 26 into proper register with the dies G2 and ld, ii. stud 'i3 is provided to engage in a cut-away portion of the shaft SS so as to lock the same in any position which may be hired by adiustment of the nut ld.

en the strip 2t leaves the left hand dies t@ and. @il it has .the contour .as shown in Figure 13, having a hooked portion 'ifi on its left side, intermediate convolutions lil, an angular extension 'lo and an opstanding dange il. vlhis contout is necessarily a function of the contour of When any de the dies 02 and il, and particularly the left han die, as shown in Figures 3 and 4.

After leaving the preforming dies 32, the strip p of the tube material. In this die case 1l are l disposed a number of die plates 19 separated from one another by spacers lll. The die plates and spacers are substantially discs in shape, having one quadrant removed, as shown in Figure 8.

The die plates and spacers are maintained in proper position by means of dowels ll which extend through appropriate openings. and are threaded into the right hand wall of the die case 1l. The die plates 19 and the spacers I0 are provided with arcuate openings I! in their centers, and instead of being fiat are convoluted. that is offset laterally, so that the resulting tube will have the desired pitch.

A bearing block 83 is provided and the die case 1l is secured to the bearing block by means of screws Il. A set screw i5 holds a sleeve li in place, and there is provided the usual ball bearing assembly 81 to permit rotation of the pulley il, the right hand side of which is provided with bayonet slots 88. A hand wheel Il having a hub s provided with pins 9| is disposed against the pulley 53, and the pins 9i are adapted to be engaged in the bayonet slots 88 for the purpose of driving the wheel I9. The hub Il is provided with screw threads il for the purpose of receiving a threaded hollow shaft Il.

Borne in the wheel 89 is a dog 93 actuated by a spring ll, the dog being provided with a laterally extending pin 9|. A lsleeve il is secured around the hub 90 and the extension of the pulley .53 is provided with a cam surface I1 against which the pin l! is adapted to ride. Threaded to the hub 0l is the hollow shaft Il formed with a plurality of slots 8! in any of which the dog s! may engage as shown in Figure 7.

A mandrel |00 is carried by the hollow shaft Sl and is provided with a very slight taper at the portion which contacts the tube material 2l. 'I'he shank of the mandrel Ill is provided with a standard Morse taper IIN to enter the hollow shaft Il. A rod |02 is threaded into the shank of the mandrel Ill and is provided on its outer end with a head having ilat surfaces so that it may be engaged by a wrench for the purpose of adjusting the mandrel lil. The right hand end of the hollow shaft 9| is provided with a hand adjusting wheel I held in place by a set screw III.

In the tube forming operation the preformed strip 2l is set into the dies 10,.,which, as best shown by Figure 10, are of a shapeto form the contour oi' the strip. The actual tube forming operation is performed by the die which receives the hook portion 1l of the strip, and folds it over on to the extension 11 of the preceding convolution. As the strip 2O enters the ,forming die the thread of solder 31 is passed into the seam so as to lie at the junction of the olf-set portion and the annular ange 11 of thestrip 2l. Figure 19 shows the contour of the die which forces the hook portion 14 on to the nange 11.

As the material enters the die 1l itrides against a cam face |01, which gradually emerges from the shape shown at ll1 to the square shape as shown at Il.. -This causesv the hook portion 1I incorporated in the seam, as shown in Figure 14. When the folding action is complete the outside diameter of the finished seam |06 is the same as the outside diameter of the free intermediate convolution 1l.

The entire movement of the strip 'material 26 through the forming dies and .through the preforming dies, is by virtue of the friction between the mandrel llil and the material in the process of being formed. In order to start or stop the mandrel |00 it is necessary only to rotate the sleeve so that the pin 85 rides up on the cam l1, and disengages 'the dog 93. The hand wheel I9 may then be turned so as to disengage the pins 9i from the bayonet slots Il of the pulley 53. Upon retraction of the wheel Il to the. right, as shown in Figure 6, it carries with it the hollow shaft Il.

As the finished seam lili is progressively completed, the tube moves to the left and may be immediately heat treated as shown in Figure 2, or any desired length of the finished tube may be made and subsequently treated as a separate operation. v

After the completed tube has been heat treated, it is desirable to compress the same longitudinally so as to afford greater flexibility without imposing strain on the seam |08. Referring to Figures 15 and 16, a fixed bracket |08 is provided, which holds one end of a shaft H0. The shaft I il may be rigid, but it is preferably an untempered flexible shaft. The tube 54 is slipped on the shaft Ill and a sliding block ill is provided to compress the tubing. The block lli may be operated by mechanical power, but it has been found very eillcient to force the block III against thesend of the tube by manual pressure. 'I'he compression of the tube reduces the length of the tube by approximately 40%, and causes a change in the pitch at the convolutions. The free convolutions are then curved in cross-section, as shown in Figure 17, and the the die plates 1l and the spacers l0, various types to be folded over with the thread of solder 31 75 of tubing may be made, as for example, that shown in Figure 18, in which the seam is at the base of the convolution, rather than the crown. Likewise, by,appropriate substitution of die plates 1l, tubing may be formed having two or more convolutions intermediate of each seam. Tubing of varying diameters may be made on the same machine by the substitution of different sizes of die plates 1l and spaces Il, together with a corresponding substitution of the mandrel IIII for a ldifferent size.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a machine for making flexible tubing, a

forming die comprising a die casing, a plurality forming die comprising a die casing, a plurality cally twisted changeable die plates thereoi. heli in. a plurality ofA separate similarly twisted changeable spacer plates separating said die l plates to facilitate the formation of tubes of .Y

various sizes, a mandrel to feed material for forming a tube to the die plates, and means to drive the mandrel.

3. In a machine for making flexible tubing, a forming die comprising a die casing, a plurality of convoluted die plates therein, a plurality of plates, said die plates being substantially disc shaped and having a sector thereof cut away and having an arcuate opening in the center thereof, a mandrel to feed material for forming a tube through the die casing, and means to drive the mandrel.

' 4. In a machine for making nexible tubing, a forming die comprising a die casing, a plurality of helically flexed die plates therein and a plu rality of spacer plates of lesser diameter separating said die plates, said die plates being substantially circular, lacking a sector and having an opening in the center thereof, a mandrel to feed material for forming a tube to the die, and means to drive the mandrel, the wall of said opening being on a curve to control and define the pitch of the convolutions of the tube.

5. In a machine for making exibie tubing, a

lforming die comprising a die casing, a plurality of die plates therein, a plurality of spacer plates separating said die plates, a mandrel to feed material for forming a tube to the dies, means to drive the mandrel comprising a hollow shaft to carry the mandrel, a drive pulley, a collar to drive the shaft, and connecting means between the collar and said drive pulley.

6. In a machine for vmaking'exible tubing, a forming die comprising a die casing, a plurality of die plates therein, aplurality of spacer plates separating said die plates, a mandrel to'feed material for forming a tube to the dies, means to drive the mandrel comprising a hollow shaft to carry the mandrel, a drive pulley, a collar to drive the shaft, and a d'isengageable connecting means between the collar and said pulley.

7. In a machine for making flexible metallic tubes, a former headincluding a die casing, a plurality of dies therein having spacers therebetween, a mandrel to feed a preformed metal strip to the dies to form coils therefrom, a sleeve enclosing said mandrel, a drive pulley, a collar iixed on said sleeve and having disengageable connections with said pulley, means lto apply solder to the strip as it advances between said dies, and means for heating the coils to fuse the solder.

8. In a machine for making flexible metallic tubes,.a former head including a die casing, a plurality of dies therein having spacers therebetween, a power driven mandrel to move said strip into engagement with said dies, means to engage and disengage the power drive to said mandrel, a flux bath throughl which said strip is drawn, wipers to remove excess`fiux from the surfaces of said strip prior to passage into the dies, means to supply a thread of solder to the strip as it advances into said dies, means to lubricate the strip in its passage between said dies, and means to cause the solder-to coalesce with the edges ofthe strip upon-its emergence from the dies. v

9. In a machine for making flexible metallic tubes, a former head including a die casing, a plurality of paired dies in said casing, a mandrel to move a Apreformed single unitary metal strip between said dies, said dies being replaceable and having spacers therebetween, a tank containing a bath of liquid rlux through which the strip independent spacer plates intermediate said die passes, means to remove excess ux from each side of the strip, means to preform the strip prior to entering said dies, means to apply a thread of solder to one of the edges of said strip while passing through said dies, and means to melt' the solder upon emergence of the tube formed by said dies. 10. In a machine for making fiexible metallic tubes from a single unitary metal strip, a series oi pairs of dies for progressively forming the strip to present opposed interengageabie edges and one or more channelled wales spaced parallel therewith, a power driven mandrel on which the strip is coiled upon its passage from said dies. a plate die casing, a plurality of substantially circular plate dies spaced uniformly in said casing and disposed circumjacent said mandrel and coil, said plate dies progressively causing seam interlocking of the strip edges and rectlncation of the intervening Wale or wales to form a uni; form helically convoluted tube.

1l.. In a machine for making exible metallic tubes from a single unitary metal strip, a series of pairs of dies for progressively forming the strip to present opposed interengageble edges and one or more channelled wales spaced intermediate the edges, a controllably driven mandrel on which the strip is tightly coiled as it emerges from said dies, a. casing, a plurality of plate dies fixed in said casing, spacers arranged therebetween, said plate dies being substantially threequarters of va circle, helically shaped in cross section, concentric with said mandrel and adapted to cause the edges of the strip to interlock forming a helically convoluted tube, means to supply lubricant Ato the tube during its passage through said plate dies, and means to seam the inter,

locked edges with solder.

l2. In a machine for making flexible metallic tubes from a unitary metal strip. a series of revoluble dies to progressively form the strip with opposed interengageable edges and a continuous raised wale therebetween, a rotating mandrel to grip the strip and cause its advancement through the dies, a housing around said mandrel, a series of cam disc formers fixed in said housing to progressively cause interlocked engagement of the strip edges, said cam discs coiling' the strip around the mandrel in uniform convclutions with its Wale intermediate thereto, means to enter a thread of solder between the interlocked edges of the strip, means to supply lubricant to said cam disc formers, and means to set the solder.

13. In a machine for making ilexible metallic tubes from a unitary metal strip, a series of revoluble dies to progressively form the strip with opposed interengageable edges and a continuous raised Wale therebetween, a rotating mandrel to grip the strip and cause its advancement through the dies, a housing around said mandrel, a series of cam disc farmers fixed in said housing to progressively cause lnterlocked engagement of the strip edges, said cam discs coiling the strip around the mandrel in uniformA convolutions with its Wale intermediate thereto, means to enter a thread of solder between the interlocked edges of the strip, and a high frequency electrical induction tube through which the coils are l passed to melt the solder.

14. In a machine for making flexible metallic tubes from a. continuous strip having preformed interengageable edges and a raised central channel, a. rotating mandrel, a series of cam plates about said mandrel, said mandrel drawing the strip through said plates unseamingthe edges and rectifying the channel, said cam plates shaping the seam and channel to present uniform convolutions.

15. In a machine for making flexible metallic tubes from a strip, a rotatable mandrel, a. die therearound, said mandrel drawing the strip through said die, said die having means to interfold the edges of the strip at alternate convolutions of the tube, the intermediate convolutions' 6 terfolded convolutions hermetically sealed.

ALBERT F. LAPP. HERMAN SHELLMER. 

